int button_up = A0;
int button_down = A5;
int light = 0;

void setup(){
  Serial.begin(9600);
}

void loop(){
 if(digitalRead(button_up)){
   Serial.write("0");
   while(digitalRead(button_up)) {
     delay(100);
   }
 }
 if(digitalRead(button_down)){
   Serial.write("1");
   while(digitalRead(button_down)) {
     delay(100);
   }
 }
}
